DISSERTATION RESEARCH: How do plant genetics, soil microbes and the environment determine plant and soil function across global change gradients?

植物的气候变化对其环境的影响以及植物在新环境中的成功不仅取决于它们的遗传，还取决于它们与土壤生物的相互作用。了解植物遗传学如何与压力条件下的生长有关，以及土壤中是否含有促进或减少植物生长的“朋友或敌人”，是预测环境和经济上重要植物未来成功或失败的关键。该项目将探索植物遗传学和土壤生物（细菌和真菌）如何帮助植物在现有环境中表现良好，或者在当前环境变得更加紧张的情况下帮助它们在新的环境中表现良好。该项目以15年的研究为基础，展示了不同类型地区植物、土壤生物和土壤肥力之间的遗传联系。这些遗传联系维持了植物和土壤生物的多样性，并决定了能量如何在大范围内通过生态系统流动。研究结果将为土地管理者提供基本的见解，了解树木如何应对环境压力，如气温上升、更长更严重的干旱以及氮污染。鉴定影响植物健康的土壤生物将适用于广泛的环境变化问题。这项研究将提供多种实验室和现场技术的培训，并为几名本科生提供开发独立研究项目的机会。随着环境的快速变化，今天很好地适应了地点的植物种群在未来可能会在当地不适应。由于压力导致植物种群适应或迁移到更有利的栖息地，预测适应将依赖于对遗传多样性模式的理解，而迁移将由影响物种范围动态的因素决定。由于植物同时经历多种影响其生长性能的非生物和生物环境，因此在包括土壤细菌、真菌和古细菌（即土壤微生物组）等相互作用物种的现实条件下研究遗传资源至关重要。目前的研究表明，植物-土壤-微生物组联系的遗传变异将决定地上和地下系统如何响应全球变化。本研究的目的是发现植物遗传和土壤微生物组机制，这些机制允许或阻碍植物适应和迁移以响应环境变化。为了实现这一目标，该项目将进行一项温室实验，以表征植物基因-土壤微生物-非生物环境的相互作用，沿着温度、水分可用性和土壤氮的实验梯度，基于先前的实地调查。研究人员将测量植物和土壤对梯度的反应、植物-土壤调节效应以及土壤群落对重要生态植物性状的影响。此外，他们还将确定植物基因型、土壤微生物组和非生物环境的特定组合，这些组合会对植物生产力和营养动态产生非加性影响。该方法将为以下方面提供重要的生态反馈：1)植物对非生物胁迫的非加性反应；2)植物遗传变异和土壤微生物系统发育多样性的维持；3)土壤养分库（如碳和氮）的恢复力和稳定性。

How well plants weather changes to their environment and the success of plants in new environments will depend not only on their genetics but also on interactions with soil organisms. Knowing how plant genetics relates to growth in stressful conditions, and whether soils contain "friends or foes" that improve or reduce plant growth is key to predicting the future success or failure of environmentally and economically important plants. This project will explore how plant genetics and soil organisms (bacteria and fungi) can help plants perform well where they are now or help them in new sites if their current environment becomes more stressful. This project builds on 15 years of research demonstrating genetic links between plants, soil organisms and soil fertility in different types of places. These genetic links maintain the diversity of plants and soil organisms and determine how energy flows through ecosystems at large scales. The results will provide land managers fundamental insights into how trees respond to environmental stresses, such as rising temperatures, longer and more severe droughts, and nitrogen pollution. Identification of soil organisms that influence plant health will be applicable to a wide range of environmental change issues. The study will provide training in diverse lab and field techniques and opportunities to develop independent research projects to several undergraduate students. With the rapid rate of environmental change, plant populations that are well adapted to sites today are likely to be locally maladapted in the future. As stress causes plant populations to adapt or migrate to more favorable habitats, predicting adaptation will rely on understanding patterns of genetic diversity, while migrations will be determined by factors that influence species range dynamics. Since plants experience multiple abiotic and biotic environments simultaneously that affect their performance, it is critical to study genetic resources under realistic conditions that incorporate interacting species such as soil bacteria, fungi, and archaea (i.e., the soil microbiome). Current research shows that genetic variation in plant-soil-microbiome linkages will dictate how above- and belowground systems respond to global change. The goal of this study is to discover plant genetic and soil microbiome mechanisms that allow or impede plant adaptation and migration in response to environmental change. To achieve this, the project will conduct a greenhouse experiment to characterize plant genetic-soil microbe-abiotic environment interactions along experimental gradients of temperature, water availability, and soil nitrogen based on previous field surveys. Researchers will measure plant and soil responses across the gradients, plant-soil conditioning effects, and soil community effects on ecologically important plant traits. In addition, they will identify specific combinations of plant genotypes, soil microbiomes, and abiotic environments that result in nonadditive effects on plant productivity and nutrient dynamics. This approach will provide insight for ecological feedbacks that are important to: 1) non-additive responses of plants to abiotic stressors; 2) the maintenance of plant genetic variation and soil microbial phylogenetic diversity; and 3) resilience and stability of soil nutrient pools (e.g., C and N).